Belt feed mechanism for rapid-fire guns



J. R. STEPHENSON BELT FEED MECHANISM FOR RAPID FIRE GUNS April 5, 1949.

4 Shets-Sheet 1 Filed Sept. 22, 1944 IN V EN TOR.

m\ N L R w J flm/// @l w .M i Q MNK qwm w wmww Po r April 5, 1949 J. R. STEPHENSON BELT-FEED MECHANISM FOR RAPID FIRE GUNS Filed Sept. 22, 1944 4 Sheets-Sheet 2 INVEN TOR.

J. R. STEPHENSON BELT FEED MECHANISM FOR RAPID FIRE GUNS April 5, 1949.

4 Sheets-Sheet 3 Filed Sept. 22, 1944 IN V EN TOR.

April 5, 1949. J. R. STEPHENSON BELT'FEED MECHANISM FOR RAPID FIRE GUNS 4 Sheets-Sheet 4 Filed Sept. 22, 1944 IN V EN TOR.

Patented Apr. 5, 1949 BELT FEED MECHANISM FOR RAPID-FIRE GUNS James R. Stephenson, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a

corporation of Delaware Application September 22, 1944, Serial No. 555,214

9-Claims. 1

This invention relates to ordnance and more particularly to an improved mechanism for feeding the cartridges into a 50-caliber Browning machine gun.

One object of this invention is to simplify the procedure required to convert from righthand feed to left-hand feed.

Anotherobjectof this invention is to provide a convertible belt feed mechanism which eliminates the need for the usual bolt switch heretofore used.

A still further object of this invention is to strengthen the bolt in one of its weak places.

Another object of this invention is to increase the rate of fire of a 50-caliber Browning machine un.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention isclearly shown.

In the drawings:

Fig. 1 is a fragmentary elevational view, with parts broken away, so as to show the arrangement of my improved belt feed mechanism relative to the other parts of a conventional -50-caliber Browning machine gun;

Fig. 2 is a plan view of a bolt constructed in accordance with my invention;

Fig. 3 is a fragmentary View, with parts of the cover broken away, showing my improved belt feed lever mechanism mounted in a conventional n;

Figs. 4 and 5 are sectional views showing the arrangement of the belt feed slide assembl for right-hand and left-hand feeding respectively;

Figs. 6 and 7 show various positions occupied by the belt feed lever mechanism when arranged to feed cartridges from the left side to the .right side;

Figs. 8 and 9 show various positions occupied by the belt feed lever mechanism when arranged to feed cartridges from the right side to the left side;

Fig. 10 is a plan view of the belt feed lever base;

Fig. 11 is an elevational view of thebelt feed lever base;

Figs. 12 and 13 show the construction of the base retaining key; and

Fig. 14 is a fragmentary sectional view taken on line I l-l4 of Fig.9.

Referringnow toFig. 1 .of the drawings wherein ,I haveshown .a preferred embodimentof m invention applied to a conventional ED-caliber Browning machine gun, reference numeral *Zll designates a conventional breech housing provided with the usual cover 22 which pivots about the pin 24. Reference numeral 26 design-ates the conventional cover latch which normally holds the cover in its down position. The cover construction has not been changed in any material manner and for that reason needs no further description. The belt feed slide assembly 28 which is also of conventional construction is slidably mounted in the guideways 3!! provided in the cover. The belt feed slide assembly includes the conventional belt feed pawl 32, pawl arm 34 and spring 36, each of which is of conventional construction and needs no further description.

In the prior art bolt construction, the top surface of the bolt was provided with a pair of intersecting belt feed lever operating ways and included a bolt switch journaled within a recess provided in the upper surface of the bolt at the point of intersection of the two ways. As shown in Fig. 2, my improved bolt generally designated by the reference numeral 4|] is provided with only the one way 42 constructed as shown. Thus, v.I have eliminated one of the ways and have eliminated the bolt switch. Again referring to Fig. 2, it is apparent that the upper surface .of the bolt does not require a bearing for the boltswitch. It is also apparent that portions 44 and 46 .of the upper bolt surface ma be cut away so as to reduce the weight of the bolt. By reducing the weight of the bolt the rate of fire of the un is increased and by eliminating the switch bearing aperture the bearing for the extractor which formerly was one of the Weak points of the gun has been strengthened.

In order to facilitate changeover from righthand feed to left-hand feed without'the-use of a bolt switch and a pair of intersecting ways, ,I have changed the construction of the belt feed lever so as to make it possible to changeover from right-hand to left-hand feed .merely by changing the belt feed lever mechanism which is carried by the cover and is easy to .get at when the cover is raised.

Referring now to Figs. 6 through 9 of the drawings, it will be noted that the belt feed lever mechanism comprises a first lever 50 pivoted about the pin 52 and a second lever '54 .which may be keyed to move with the lever 50 so its to pivot about the pin ,52 or may be caused to pivot about the auxiliary pin '56. Thus,-the-.two levers 50 and 54 may be operated as one single jection 5| which extends into the way 52 and -5 the lever Ed is provided with .a projection 55 sible to operate the two levers together as one lever or to operate the two levers as separate '52 so as to be rotatively supported on the pin and the base 58 are keyed together in inann v as shown in Figs: 8 and 9. Rate .with a key slot 62 for the reception of Each of the leversfiil and 5 -3 is provided with moved from the slot 5-2. so asto allow the lee to operate as separate levers the its of the base filiise'e: Figs lll, and- 1) so lock the base 58- as.

- 'tion of the belt feed lever in any one belt' feed lever operated or the two levers may lrie opeiated as two separate levers geared to one another. The level-'59. is provided with a pro 1 which extends into one of the notches ii! provided in the slide 28. In order to make it pos-- ll) levers, abelt feed lever baseEB has been added which is provided with a solid bearing pin 56 I and a hollow bearing to which slips onto the pin 52. The pin 52 is'carried by the cover 22 and is identical in construction with thecorrespond ing pin used in the priorartgun.

When it desired to feed the cartridges in the gun'from the left side, the levers and to beexplained more full hereinaft operate as a single lever pivoted on iso as and '14 of the drawings, it wz the uppersnrface: of the base is prov.

such as the key 556 shown in Figs. i2 2 and i key siot invite under sidesuc'n asthe key sic illustrated in Fig. 14.

' When it is desired to feed the cartr the gun from the right side, the key 1 then inserted into a slot ES provided in one s v 35 .n'st movement about ti As a consequence of this chap" d causes the lever 56 to rotate in the op direction about the pivot pin e a of the drawing show the operation or the when the base it held against Cation by key 64 whereas Figs. 8 and 9 show the operai' of the levers when the key is used to the levers together.

The location of the key as may be changes by raising the cover 22 and removing the has 58 together with the associated parts from th-v pivot pin 52. Removable cotter keys GS and '5 (see Fig. 1) are used to hold the levers assembled relationship.

Referring to Fig. 12 of the drawings, it will be noted that the key fi l slightly tapered that teeth or lugs '52 are provided adjacent the one end of the key which are adapted to mesh with the teeth or lugs "l lwhich have been. provided on the base 58. The teeth serve to loci: the key in any one of several positions in the slot 68. The purpose of the taper is to compensate for difierences in the amount of clearance between the pin 52 and the side wall of the cover 22 in different guns.

By virtue of the above described arrangement, only one size key needs be made and the one lacy may be used to serve either of two purpose; spare parts need be carried to change V1. right-hand feed to left-hand reed and the p are easily changed from the one arrangement to the other. 70

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of'the claims which follow.

pin 52.

gun, a first element constituting a support for said'mechanism, said support including a mounting pin, a secondelement constituting a belt feed lever bas carried by said pin, said base having a slot provided in the one face thereof, a key within saidslot having one edge arranged atan angle to the opposite edge thereof, one of said edges being disposed in said slot and the other of said edges being disposed against said support, said key and oneof'said elements hav- 'ing interlocking iugs for holding said lrey against movement lengthwise of said slot.

2. in combination, a first element including ,a .key slothaving a plurality of fixed uniform equally spaced locking lugs adjacent thereto, a

' held in predetermined re-' 'lationshi with respect to said first element, a

second element to be keyadapted to be wedged between said elements,

said key having a tapered portion and having a plurality of fined uni-form equally spaced locking lugs cooperating; and interfitting with said endwise movement in said 8101),, each of said equally spaced series locking lugs being in the form of a straightrack capable of interfitting with each other in a plurality of positions.

, 3. In a rapid f re machine gun, a breech housing, a cover for said housing, a reciprocating bolt within said housing, belt feed lever mechanism carried by said cover, said bolt having a I belt feed lever guideway in its-upper surface ar ranged in ,engagementwith that belt feed lever vmechanisni, a belt feed slide assembly slidably I v I carried by said cover andarranged to be operated by said belt feed lever mechanism, a {or said belt'feed lever mechanism pivotally mounted on the underside of said cover, means for locking said base against rotation when feeding-of the belt in the one direction is desired, said last named means including a tapered key wedged between a portion of said base and a portion of said cover, said base having a pair of pivot said belt feed lever mechanism including a pair of levers pivoted on said pins, said levers including inter-meshing gear teeth whereby rotation of one of said levers about its pivot pin in one direction causes rotation of the other lever in the opposite direction when said base is locked against rotation, and means for preventing relative rotation of said levers whereby both levers and said base may pivot in unison when feeding of the belt in the other direction is desired.

4. In a rapid fire machine gun, a breech housing, a cover for said housing, a reciprocating bolt within said housing, belt feed lever mechanism carried by said cover, said bolt having a belt feed lever guideway in its upper surface arranged in engagement with that belt feed lever mechanism, a belt feed slide assembly slidably carried by said cover and arranged to be operated by said belt feed lever mechanism, a base for said belt feed lever mechanism pivotall mounted on the underside of said cover, means for locking said base against rotation when feeding of the belt in the one direction is desired, said last named means including a tapered key wedged between a portion of said base and a portion of said cover, said key and said base including interlocking lugs for holding said key in adjusted position, said base having a pair of pivot pins, said belt feed lever mechanism including a pair of levers pivoted on said pins, said levers including intermeshing gear teeth whereby rotation of first named locking lugs forholding said hey against one of said levers about its pivot pin in one direction causes rotation of the other lever in the opposite direction when said base is locked against rotation, and means for preventing relative rotation of said levers whereby both levers and said base may pivot in unison when feeding of the belt in the other direction is desired.

5. In 'a rapid fire machine gun, a breech housing, a cover for said housing, a reciprocating bolt within said housing, belt feed lever mechanism carried by said cover, said bolt having a belt feed lever guideway in its upper surface arranged in engagement with that belt feed lever mechanism, a belt feed slide assembly slidably carried by said cover and arranged to be operated by said belt feed lever mechanism, a base for said belt feed lever mechanism mounted on the underside of said cover, said base having a pair of pivot pins, said belt feed lever mechanism including a pair of levers pivoted on said pins, said levers including intermeshing gear teeth, whereby rotation of one of said levers about its pivot pin in one direction causes rotation of the other lever in the opposite direction when said levers are free to rotate about their respective pivot pins, and means for interlocking said levers so as to cause said levers to operate as one lever whereby rotation of one of the levers about its pivot in the one direction causes rotation of the other lever in the same direction.

6. In a rapid fire machine gun, a breech housing, a cover for said housing, a bolt mounted for reciprocation within said housing, a belt feed slide assembly slidably mounted in said cover, a belt feed lever guideway provided on one surface of said reciprocating bolt, means for feeding a cartridge belt into said housing either from left to right or from right to left comprising a pair of belt feed levers, a first pivot for one of said levers carried by said cover, a second pivot for the other of said levers, said second pivotbeing spaced from said first pivot, a support for said second pivot, means for mounting said support so as to pivot about the axis of said first pivot, and key means selectively operable for locking together said first lever, said second lever and said support so as to oscillate together about the axis of said first pivot or for locking said support 'to said cover so as to prevent oscillation of said support.

7. In combination, a first element, a second element, a tapered wedge element adapted to fit between said elements, one of said elements being provided with a series of uniformly spaced fixed teeth in the form of a straight rack, another of said elements having a tooth fixed thereto adapted to alternatively engage any one of a plurality of the spaces between the teeth of said one element, said tapered wedge element being one of the toothed elements and being locked in any one of a plurality of positions between the first and second elements by the interengagement of the teeth in a plurality of alternative positions, said wedge element having a plane wedging face in contact with a plane face of the other toothed element.

8. A mechanism for changing motion including a pivot, a first member pivotally mounted upon said pivot, two lever members individually pivoted to said first member, the adjacent portions of said lever members being provided with an interfitting connection to cause the movement of one of the lever members to follow the movement of the other, and means for locking the two levers together to cause all the members to pivot upon said pivot.

9. A mechanism for changing motion including a pivot, a first member pivotally mounted upon said pivot, two lever members individually pivoted to said first member, the adjacent portions of said lever members being provided with an interfitting connection to cause the movement of one of the lever members to follow the movement of the other, locking means movable to one position for locking said first member to said pivot and movable to a second position to lock said levers together.

JAMES R. STEPHENSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Speckert Apr. 18, 1944 Moore Dec. 19, 1944 FOREIGN PATENTS Number Number 

